Micro-mechanisms of fatigue damage in copper crystals
铜晶体的疲劳损伤微观机制

Micro-mechanisms of fatigue damage in copper single-, bi- and poly- crystals were summarized in the present paper. A number of investigations reveal that fatigue crack mainly initiates along persistent slip bands (PSBs) in copper single crystals at low or medium strain range, however, nucleates along coarse deformation bands (DBs) at high strain range. For copper bi-crystals, various large-angle grain boundaries (GBs) are always the preferential sites for the nucleation and propagation of fatigue cracks while the low-angle GBs do not lead to fatigue cracking during fatigue. Fatigue cracks mainly nucleated along large-angle GBs, sometimes along PSBs in polycrystalline copper, however, the initiation of fatigue crack at twin boundaries (TBs) was not observed due to the compatible slip deformation across the TBs.